| 摘要 |
PURPOSE:To provide required information so that a user can utilize it for proper judgment by selecting a satellite with the minimum error evaluation value out of satellites which can perform measurement and then limiting the presence range of a current position and calculating the speed component of a traveling body. CONSTITUTION:First, the measurement result of a plurality of satellites demodulated by a signal-reception device 1 is input. Then, position measurement operation is performed according to the measurement data when it is judged that a satellite enabling a sufficient accuracy for determining the position at a normal position measurement is available, thus calculating the current position and speed. When it is judged that two or more satellites are available in the case where a sufficient accuracy cannot be secured at the normal position measurement, an operation part 3 performs two-satellite position measurement operation for limiting a region where the current position exists from two satellites which are capable of measuring position to a region surrounded by two straight lines. Then, the result of the position measurement operation is outputted from a display part 4. |
